Controllable chirality-induced geometrical Hall effect in a frustrated highly-correlated metal

A current of electrons traversing a landscape of localized spins possessing non-coplanar magnetic order gains a geometrical (Berry) phase which can lead to a Hall voltage independent of the spin-orbit coupling within the material--a geometrical Hall effect. We show that the highly-correlated metal UCu5 possesses an unusually large controllable geometrical Hall effect at T<1.2K due to its frustration-induced magnetic order. The magnitude of the Hall response exceeds 20% of the \nu=1 quantum Hall effect per atomic layer, which translates into an effective magnetic field of several hundred Tesla acting on the electrons. The existence of such a large geometric Hall response in UCu5 opens a new field of inquiry into the importance of the role of frustration in highly-correlated electron materials.Comment: article and supplemental informatio

The Kynurenine Pathway Is Upregulated by Methyl-deficient Diet and Changes Are Averted by Probiotics

Scope Probiotics exert immunomodulatory effects and may influence tryptophan metabolism in the host. Deficiency of nutrients related to C1 metabolism might stimulate inflammation by enhancing the kynurenine pathway. This study used Sprague Dawley rats to investigate whether a methyl-deficient diet (MDD) may influence tryptophan/kynurenine pathways and cytokines and whether probiotics can mitigate these effects. Methods and Results Rats are fed a control or MDD diet. Animals on the MDD diet received vehicle, probiotics (L. helveticus R0052 and B. longum R0175), choline, or probiotics + choline for 10 weeks (n = 10 per group). Concentrations of plasma kynurenine metabolites and the methylation and inflammatory markers in plasma and liver are measured. Results MDD animals (vs controls) show upregulation of plasma kynurenine, kynurenic acid, xanthurenic acid, 3-hydroxyxanthranilic acid, quinolinic acid, nicotinic acid, and nicotinamide (all p < 0.05). In the MDD rats, the probiotics (vs vehicle) cause lower anthranilic acid and a trend towards lower kynurenic acid and picolinic acid. Compared to probiotics alone, probiotics + choline is associated with a reduced enrichment of the bacterial strains in cecum. The interventions have no effect on inflammatory markers. Conclusions Probiotics counterbalance the effect of MDD diet and downregulate downstream metabolites of the kynurenine pathway.publishedVersio

The Kynurenine Pathway Is Upregulated by Methyl-deficient Diet and Changes Are Averted by Probiotics

Scope Probiotics exert immunomodulatory effects and may influence tryptophan metabolism in the host. Deficiency of nutrients related to C1 metabolism might stimulate inflammation by enhancing the kynurenine pathway. This study used Sprague Dawley rats to investigate whether a methyl‐deficient diet (MDD) may influence tryptophan/kynurenine pathways and cytokines and whether probiotics can mitigate these effects. Methods and Results Rats are fed a control or MDD diet. Animals on the MDD diet received vehicle, probiotics (L. helveticus R0052 and B. longum R0175), choline, or probiotics + choline for 10 weeks (n = 10 per group). Concentrations of plasma kynurenine metabolites and the methylation and inflammatory markers in plasma and liver are measured. Results MDD animals (vs controls) show upregulation of plasma kynurenine, kynurenic acid, xanthurenic acid, 3‐hydroxyxanthranilic acid, quinolinic acid, nicotinic acid, and nicotinamide (all p < 0.05). In the MDD rats, the probiotics (vs vehicle) cause lower anthranilic acid and a trend towards lower kynurenic acid and picolinic acid. Compared to probiotics alone, probiotics + choline is associated with a reduced enrichment of the bacterial strains in cecum. The interventions have no effect on inflammatory markers. Conclusions Probiotics counterbalance the effect of MDD diet and downregulate downstream metabolites of the kynurenine pathway

A Case of Tumor Lysis Syndrome after Docetaxel Administration for Recurrent Ovarian Cancer

Abstract Tumor Lysis Syndrome is a rare complication of the treatment of solid malignancies. A 51 year old female developed this condition one week after undergoing docetaxel chemotherapy for progressive, recurrent ovarian cancer. She was diagnosed based on classic laboratory disturbances including increased creatinine, hyperphosphatemia, hypercalcemia, hyperkalemia, and hyperuricemia. The patient was successfully treated with aggressive intravenous hydration, allopurinol, and rasburicase. Although uncommon, clinicians should be aware of this condition so that proper identification occurs and treatment can be implemented promptly. as this patient had a BMI over 25 (BMI 27.4, BSA 1.78). Creatinine clearance was calculated using the Cockroft Gault equation with a minimum creatinine value of 0.7 mg/dL. The Calvert formula was used for Carboplatin dosing. She received 6 cycles of dose-dense paclitaxel and carboplatin, with an initial improvement in her CA125. However, CT imaging at completion of 6 cycles demonstrated residual disease involving the chest, abdomen and pelvis and her CA125 plateaued. She was diagnosed with platinum resistant disease and was switched to a 28 cycle day regimen of gemcitabine (800 mg/m 2 , cycle days 1 and 8) and bevacizumab (15 mg/kg, cycle day1) of which she received 2 cycles. Her CA 125 count continued to rise despite this treatment, thus she was changed to a 28 cycle day regimen of liposomal doxorubicin (40 mg/m 2 , cycle day 1) and bevacizumab (15 mg/kg, cycle day 1). After 3 cycles of therapy, her disease failed to respond as evidenced by a rising CA 125. As a result, she was changed to docetaxel at a dose of 75 mg/m 2 and received one cycle uneventfully. Seven days after her first docetaxel administration, the patient presented with fatigue and decreased oral intake. She was admitted for supportive therapy for suspected chemotherapy-associated malaise. On the evening of hospital day #1 the patient reported increased shortness of breath. She was noted to be pale, hypotensive, and hypoxic. An EKG revealed new onset right bundle branch block. She was transferred to the ICU for critical care monitoring given her worsening clinical picture. TLS was diagnosed after laboratory evaluation revealed acute renal insufficiency (2.4 mg/dL) and severe electrolyte abnormalities (phosphorus 5.7 mg/dL, calcium 9.7 mg/dL, potassium 7.0 mmol/L and uric acid 10.1 mg/dL). Treatment with allopurinol, rasburicase, and aggressive hydration was promptly initiated. She received a single dose of intravenous rasburicase and started on allopurinol 300 mg BID. Six hours following administration of rasburicase, her uric acid had decreased to 2.9 mg/dL. She was continued on allopurinol for 3 days as her uric acid level continued to decrease. As her electrolyte

Polygenic risk for schizophrenia and bipolar disorder in relation to cardiovascular biomarkers

Individuals with schizophrenia and bipolar disorder are at an increased risk of cardiovascular disease (CVD), and a range of biomarkers related to CVD risk have been found to be abnormal in these patients. Common genetic factors are a putative underlying mechanism, alongside lifestyle factors and antipsychotic medication. However, the extent to which the altered CVD biomarkers are related to genetic factors involved in schizophrenia and bipolar disorder is unknown. In a sample including 699 patients with schizophrenia, 391 with bipolar disorder, and 822 healthy controls, we evaluated 8 CVD risk biomarkers, including BMI, and fasting plasma levels of CVD biomarkers from a subsample. Polygenic risk scores (PGRS) were obtained from genome-wide associations studies (GWAS) of schizophrenia and bipolar disorder from the Psychiatric Genomics Consortium. The CVD biomarkers were used as outcome variables in linear regression models including schizophrenia and bipolar disorder PGRS as predictors, age, sex, diagnostic category, batch and 10 principal components as covariates, controlling for multiple testing by Bonferroni correction for the number of independent tests. Bipolar disorder PGRS was significantly (p = 0.03) negatively associated with BMI after multiple testing correction, and schizophrenia PGRS was nominally negatively associated with BMI. There were no other significant associations between bipolar or schizophrenia PGRS, and other investigated CVD biomarkers. Despite a range of abnormal CVD risk biomarkers in psychotic disorders, we only found a significant negative association between bipolar disorder PGRS and BMI. This has previously been shown for schizophrenia PGRS and BMI, and warrants further exploration

Vision Issues and Space Flight: Evaluation of One-Carbon Metabolism Polymorphisms

Intermediates of the one-carbon metabolic pathway are altered in astronauts who experience vision-related issues during and after space flight. Serum concentrations of homocysteine, cystathionine, 2-methylcitric acid, and methylmalonic acid were higher in astronauts with ophthalmic changes than in those without (Zwart et al., J Nutr, 2012). These differences existed before, during, and after flight. Potential confounding factors did not explain the differences. Genetic polymorphisms could contribute to these differences, and could help explain why crewmembers on the same mission do not all have ophthalmic issues, despite the same environmental factors (e.g., microgravity, exercise, diet). A follow-up study was conducted to evaluate 5 polymorphisms of enzymes in the one-carbon pathway, and to evaluate how these relate to vision and other ophthalmic changes after flight. Preliminary evaluations of the genetic data indicate that all of the crewmembers with the MTRR GG genotype had vision issues to one degree or another. However, not everyone who had vision issues had this genetic polymorphism, so the situation is more complex than the involvement of this single polymorphism. Metabolomic and further data analyses are underway to clarify these findings, but the preliminary assessments are promising

Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice

We report a study of the low temperature bulk magnetic properties of the spin ice compound Dy2Ti2O7 with particular attention to the (T < 4 K) spin freezing transition. While this transition is superficially similar to that in a spin glass, there are important qualitative differences from spin glass behavior: the freezing temperature increases slightly with applied magnetic field, and the distribution of spin relaxation times remains extremely narrow down to the lowest temperatures. Furthermore, the characteristic spin relaxation time increases faster than exponentially down to the lowest temperatures studied. These results indicate that spin-freezing in spin ice materials represents a novel form of magnetic glassiness associated with the unusual nature of geometrical frustration in these materials.Comment: 24 pages, 8 figure